Radiotelegraphy



' L. F. FULLER.

' RADIOTELEGRAP HY. APPLICATION FILED SEPT.23, I9I8.

1,352,059. r PatentedSept. 7, 1920.

WITNESS INVENTOR V Lf? (VALE/F m/ m BY A ATTORNEYS telegraphy,

:ing and particularly UNITED, STATES PATENT OFFICE.

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Specificationof Letters Patent. 011211131 application filed April 23, 1917, 861'181 No. 163,798. Patent No. 1,830,254, dated February 10, 1920.

Patented Sept. 7,1920.

Divided, and this application nled September 28, 1918.- Serial No. 255,245.

To all whom it may-concern Be it known-that I, LEONAR'D F. FULLER, a

citizen of the United States, and a resident of Palo Alto, county of- Santa Clara and State of California, have invented certain new and useful Improvements in Radioof which the following is a specification. 4

This application is a divislon of ap phcaatent .tion Serial No. 163,793 filed in the Oflice on April 23, 1917, and patented Feb.

v.10 1920, No.'1,330,254.

e invention relates to means of signalto means for signaling with are radio transmitters. An object of the invention is to provlde a signaling apparatus for high powered sta-' tlons.

'Another object of the invention is to provide means The invention possesses other advanta- 7 'geous features, some of which, with the foreselected for illustration in oing, will be set forth at length in the fol- OWlDgdGSCIiPtlO ,where I shall outline in full that form of the invention which I have the drawings acpart of the present com an 'n and formin P yl g understood how specification. It is to ,ever, thatthe invention'as expressed in the claims, is not ,limitedto the speclfic embodii a modified form of the's stem;

am aware, it has Heretofore, as far as m arc radio transbeen considered essential .mitters, tokeep af'practically constant radio-; frequency loadkon. the arc converter, when signals-are being sent out. This. has-been acconiplishedin two ways; first,"by the compensatlon method in which the arc is constantly loaded upon the antenna and the inductance in the antenna circuit varied andsecond, by the absorbing circuit method, in

"which'alocal non-radiating oscillatory ciris shunted around thearc, the constants o the circuit being socuit provided with a ke adjusted that -when the key is closed,'the are for 's'gnaling by manipulating the direct current circuit.

'ing and setting .tionsin theantenna. Thus the current in cuit or the antenna circuit, to the complete dling of radio-frequency currents at telegrifhic speed.

' y present mvention provides a means of signaling which necessitates the handling atte e graphic speed of only the current which feeds the are, which maybe direct current or alternating current, and this current may be easily handled.

In Fig. 1, I have shown one form of apparatus for signaling, by manipulating the are feeding current, which in this instance, is direct current. The transmission system includes anarc oscillation generator2 capable of producing continuous oscillations, havin a negative electrode 3 which is grounded an a positive electrode 4 which is connected to the antenna 5 through the variable inductance or loading coil 6. Direct current is supplied to the arc-by the generator 7, in the leads of which, choke coils 8 are placed. The-arc is subjected to a strong transverse magnetic field produced by the winding 9 arranged in the negative lead. shunting the arc is a circuit containing a variable -resistance 12, and means are provided for aagening and closing the resistance circuit.

hen the resistance'ci'rcuit is closed, the

current is shunted through the resistance 12, which is so adjusted 'that O FEDERAL TELEGRAPH- CALIFORNIA, A- CORPQRATION OF CALIFORNIA.

the load on thegenerator 7 remains the same aswhen the resistance circuit is open, and the arc isburnup radio-frequency oscillathe arc ma et windi'ng9 is held constant, a feature which is necessary on account of the large inductance of the winding. This lar e inductance sets up a large voltage across t e are and this voltage or inductive kick, is"

suificient to reignite the are when the vshunt circuit is opened. When the electrodes are cold however, and there is no ionization of theme gap due to red-hot carbon, the arc will not usually be re-ignited and some auxiliary means are usually employed to accomplish this re-ignition. would prefer to oscillate upon the local cir-.

The resistance circuit is closed and broken within the arc generator and the are produced by the opening of the resistance circuit is. employed for re-igniting the main are. In the system shown in Fig. 1, one end of the resistance circuit terminates in a movable electrode 14, arranged within the arc generator and adapted to be moved from contact with electrode 4 to contact with electrode 3 and vice versa. The other end of the resistance circuit is connected to'electrode 4, so that a movement of the electrode 14 from electrode 3 to electrode 4, makes the main arc anda' movement of electrode 14 from electrode 4 to electrode 3, breaks the main arc. When the electrode 14 is in contact with the electrode 3, the direct current flows through the resistance circuit andthe and this arc bows out substantially the same resistance as the arc, connected to one of said electrodes, and a arc" is extinguished. As the electrode 14 moves from electrode 3 to electrode 4, an arc is drawn which re-ignites the main arc and short circuits the resistance. The electrode 1'4 is moved from contact with one are electrode tothe other by the key 15.

In the apparatus shown in Fig. 2, the movable electrode 14, instead of belng movable from oneai'c electrode to the other, is movable into and out of contact with the electrode 4, by the key 15. The electrode 14 is preferably arranged to move atsubstantially right angles to the main arc gap, and as the resistance. ircuit is opened an arc is produced betweerij the electrodes 4 and 14 and is blown by the magnetic field into contact with the negative electrode 3, thereby igniting the main I claim 1. 'An are system for radio signaling comprising two electrodes between which an arc is formed, a resistance circuit having third electrode connected to the otherside of the arc.

- with the second arc electrode mally stationary electrodes, means for producing an arc between said electrodesand a third electrode movable alternately into contact with said stationary electrodes.

4. In an arc radio generator, two electrodes between which an arc is formed, a third electrode movable into contact with oneof said are electrodes and a power consuming circuit connected to the third electrode and to the electrode on the other side 5. An are system for radio signaling, comprising two electrodes between which an arc is formed and means for signaling, comprising a third electrode movable into contact with one of said arc electrodes. A"

6. An are system for radio signaling comprising two :lectrodes-between which an arc is formed, a resistance circuit con- .nected at one end to one electrode and a movable electrode connected to the other end of'the resistance circuit movable into contact 7 An are system for radio signaling, comprising two electrodes, aigenerator connected to said electrodes wh reby'anarc 1s LEONARD F. FULLER.

formed, a resistance circuit, and means in- 

